FR2530770A1 - SOUFFLET A PLIS - Google Patents

Abstract

THE SINGLE WALL METAL BELLOWS ARE USED TO ABSORB AXIAL, LATERAL OR ANGULAR MOVEMENTS. IT IS IN CAST METAL. USE TO GIVE THE BELLOWS A WALL OF VARIABLE THICKNESS OR AN UNDERSIDED PROFILE.

Description

The invention relates to a pleated bellows with a single

  wall made of metallic material, intended to absorb movements

  axial, lateral and / or angular

  At present, pleated bellows are manufactured from a cylindrical metal tube on which the desired corrugated profile is generated by radial discharge towards

  inside or outwards.

  by means for example pebbles supported from the outside and / or the inside which form in sections or continuously

the desired profile.

  Since the stretch that the material undergoes during forming is not constant, the wall has different thicknesses along the corrugated profile. These differences in wall thickness are inherent to the process used and result, depending on the manufacturing process used. more or less pronounced thinning of the wall on the crests, the bottoms and / or the flanks of the corrugations Depending on the place where the maximum force is used when using the bellows, this weakening of the wall thickness

  can reduce the allowable load and the service life.

  The major disadvantage, however, is that on folded bellows known, it is not possible

  to adapt the variations of the wall thickness to the con-

  stresses undergone by the material in a ripple of

bellows.

  The object of the present invention is therefore to provide a single-walled pleated bellows, on which the thickness distribution of the wall along the corrugated profile can be chosen freely and in particular to be optimally adapted to the stresses experienced by the material. in a ripple. This object is achieved according to the invention because the

bellows is poured.

  The invention is based on the surprising fact that completely abandoning the method of manufacturing by radial discharge, inward or outward, in use for 80 years

  approximately, it is also possible to manufacture

  flutes by casting, in spite of the small thickness of their wall.

  This process makes it possible to produce, with a good accuracy of the shapes folded bellows whose wall is 2 to 3 mm thick with complete freedom to give the thickness of

  the wall of local variations along the wavy profile.

  In other words, the casting makes it possible, without any restriction, to give the corrugations an optimum geometries from the technical and economic point of view. Furthermore, this process has the advantage of enabling the fabrication of much deeper corrugated profiles than hitherto. , since it is not necessary to deform the material Finally, and at no extra cost,

  will also be able to make asymmetrical

  cats, especially undercutting ones.

  Rationally, the thickness of the wall varies according to predetermined local stresses experienced by

  the material in the corrugation of the bellows It is more parti-

  sharply distributed so that the tension in the material

  about the same all along the wavy profile.

  In areas of undulation particularly stressed in pressure, it is advisable to thicken the wall locally, whereas in areas of undulation especially

  when stretched, the wall is thinned locally.

  The two measures can be combined for the purpose of

  to think of the inhomogeneous state of tension and elongation in the corrugation of the bellows, to bring it back to a lower level, that is to say to standardize the rate of tension and

elongation.

  A particularly favorable conformation is

  characterized by the fact that the undulations of the bellows

  wall thicknesses both on their vertices and on the flanks. Indeed, research has shown that high meridian tensions appear not only in

2530770-

  the internal and external vertices, but also pretty much

  in the middle of the flank, especially when the bellows is

cited by pressure.

  As materials, one can primarily use for cast bellows, austenitic cast iron,

  light metal cast iron, cast iron and bronze.

  Other features and benefits derive from the

  following description of various embodiments.

  In the accompanying drawings, given by way of non-limiting examples,

  FIGS. 1 to 17 each represent a form of corrugation

  different cross-sectional

  bellows plisil is axial cuts).

  FIG. 1 shows local thickenings on the inner and outer peaks as well as on the median side of the sidewall. It is thus possible to optimally equalize the meridian tensions which appear in bellows stressed in pressure, so as to standardize and bring back to a higher level. low inhomogeneous state of tension and elongation.

  Figures 2 and 3 show the correct

  corresponding to the wall thickness with reduced meridian voltage, and respectively for relatively high pressures

  on bellows with membrane or torus.

  In large diameter bellows, it is the

  which limit the allowable pressure.

  Until now it was necessary to install separate reinforcement rings in the hollows of the corrugations.

  incorporating reinforcement rings into the wall of the

  4 to 10, the additional costs of manufacturing and setting up the reinforcement rings are avoided. Such bellows are suitable for forces

  high perimeters can therefore be achieved at a much better rate.

their market.

  The wave profile of FIG. 7 is furthermore

  asked for high movement demands, given

  that the vertices have walls thinner than the flanks.

  A wall thickness pattern for torus bellows which corresponds to that of FIG. 7 is shown in FIG. 11 and for membrane bellows in FIG. 2. If a high pressure resistance is required at the same time as high mobility, a wavy profile with no inflection points and a meridian arc length

  The largest possible is advantageous. Such a profile is

  shown in Figures 12 and 13 Profile shapes

  corresponding figures are shown in Figure 2 for

  diaphragm flutes and in figure 14 to 17 for bellows

to torus.

Claims (6)

  1 one-ply bellows of metal material for absorbing axial, lateral and / or   angular, characterized in that the bellows is cast.   Bellows according to Claim 1, having a thickness of   different king in the regions of the tops and flanks, characterized in that the wall thickness varies according to local stresses to the material in the undulation of the bellows.   Bellows according to claim 2, characterized in that   that the wall thickness is modified in the sense of a tendency   maximum uniformity on the corrugation of the bellows.   Bellows corrugation according to one of the claims   preceding, characterized in that the wall is thickened in areas of the corrugation Iqui are solicited so preponderant to the pressure.   Bellows according to one of the preceding claims,   characterized in that the wall is thinned in the areas of the corrugation which are stressed in a preponderant manner to lengthening.   Bellows according to one of the preceding claims,   characterized in that the corrugations of the bellows have both on the tops and sides of the thickenings of the wall.   Bellows according to one of the preceding claims,   characterized in that it consists of austened iron   nitric, cast of light metals, cast iron or cast bronze.